There is a lot of buzz about the idea of 3D printing taking over as the prime manufacturing method for producing products, even buildings. Some proposals include the concept of entire products being made within one machine. While the ideas are interesting and enticing, their is a long list of things that make all of this more fantasy than reality.
While the cost of 3D printed parts has been improving over the last decade, they still fall well short of the piece part prices of production tooled parts. Ignoring the cost of tooling for a moment, the cost of a stamped, die cast, or injection molded part, run in quantity, is pennies on the dollar compared to 3D printed parts.
The time that a 3D printer takes to make a part is measured in hours, compared to seconds for parts coming from tooled processes. A die cast machine, from raw material to cooled, ready to finish part might be a few minutes. Not that die cast and molding processes have a small amount of waste – as do 3D printed parts that have build trays to discard every few parts, and material that is not used from spools tails.
These two basic elements of part creation are just the beginning of the comparison lop-sidedness that ahs to be considered before running off an buying a 3D print farm.
Note also that there will always be components that are better made using other processes, such as electronic assemblies, where 3D printing becomes a complex tangle of technologies that cannot match the extremely low cost of competitive manufacturing.
Process Cross Over
While the 3D print community is convinced that printers can do everything, this assumes that the engineering of products is redesigned around 3D print processes, not a straight cross from one to the other without further consideration. In the real world, 3D printing does not cross over a wide enough number of processes to say that it is a true do-all approach.
The Magic Do-All Machine
The idea that one machine might produce every component within a product, such as a luminaire, is a wonderful image, but misses some very significant problems that will need to be overcome. The first of which is that current 3D print processes are very limited in the material they work in, and the products they can produce.
Machines that make metal parts cannot make plastic parts. Machines that make durable plastic housings well, do not do optics well, as they don’t share the technology that makes the two parts work well.
To realize a single machine that can produce all of the parts within one machine means having a machine that includes several print technologies within one massive device. Since many of these machines will cost hundreds of thousands per technology, the end resulting super Do-All printer will cost in the millions.
Series Process vs Parallel Path
A single machine making product will use a hybridized series parallel process, where parts from one technical section are passed down to the next (serial), but all operate at full capacity to make the cycle time delay only that of the longest part process in the chain, plus cycle transfer time (the time it takes to move the parts within the machine.
If we look at this from a conventional scheduling perspective, the slowest machine process becomes the bottle neck, to which the timing of all surrounding related parts will be subject. But this is not conventional processing.
In the 3D print Do-All machine, you would just add additional stages for the slowest processes, to match the speed of the fastest in the system. For example, if Process A takes 1 hour to make a part, Part B 2 hours, and part C 6 hours, you would build a machine that had (1) Part A station, (2) Part B stations, and (6) Part C stations. Now, the machine will spit out (1) complete part at the pace of the Part A station of 1 per hour. This is how the auto industry gets to making a car in 45 minutes. The car actually takes many hours to build, but through process management, can push one off the line every 45 minutes. In the 3D print Do-All machine, you would build this into the machine itself.
But Wait a Minute – How does this cut tooling cost again?
So, we move from a pile of discrete tools to make molded or stamped parts – costing tens of thousands each, operated on millions of dollars of equipment, to a 3D print D-All super machine that has no tooling, but will cost millions in and of itself.
The real advantage is not just elimination of tooling itself, but to eliminate the restrictions that tolled components put on production of parts and assemblies. Making changes, updating, or customization with hard tooling is nearly impossible, and often prohibitively expensive. 3D printing runs from files, not tools, so can be updated, modified, customized and adjusted, with no real cost penalty.
This means that, while the cost of the equipment, and the management of it as a complex series of technologies at work, the ability to integrate customization without penalty, is a very attractive benefit.
Real of Fantasy?
The capability of 3D printing is very real, for applications where customization, and short production run quantities are sought after benefits.
So, for full production replacement in high volume products, commodities, etc. that do not benefit from customization, 3D printing will likely not make any real inroads or make a significant impact.
In the world of customization to meet customer demands, for short run products, 3D printing is going to change the world. Even without the Do-All super 3D printer described here, there is a case to made for 3D Printing for product making.
The Hybrid Reality
Just as it is with the example luminaire shown in these examples, every product is a mix of parts. A product made with standard guts made using the lowest cost conventional production-in-bulk quantities, wrapped and put into service in products using 3D printing to produce the customization needed to satisfy customers, is the likely hybrid solution that will dominate for some time to come. As 3D printing technology improves in both cycle time and cost, the deeper it will reach into the standard component levels. But, for now, that reality is a fantasy.